Water soluble powders and tablets based on amorphous carbohydrate matrices are used in many fields. For example, such powders or tablets in a form suitable for human consumption are used in the food, beverage, nutrition, confectionery and pharmaceutical fields. Alternatively the powders or tablets may contain materials such as detergents intended to be dissolved or dispersed in water before use. In many cases, it is desirable that the powders or tablets should dissolve or disperse rapidly on contact with water and, for example, poor tablet dissolution is known to account for many drug-bioavailability problems. The powder or tablet may contain a chemical dissolution aid and such aids are generally combinations of chemicals which are stable in solid form but which generate a gas on contact with water, for example the combination of an acid and a carbonate or bicarbonate. In some cases, the amount of the gas-generating chemicals added is such as to provide effervescent powders or tablets.
One particular type of water soluble carbohydrate powder is soluble foamer and creamer powders which upon addition of a liquid are able to provide a creamy foam and such powders have many uses. For example, they may be used to provide milk shakes or cappuccino style beverages or they may have food applications such as in desserts, soups and sauces. Soluble coffee beverage products which produce cappuccino-type beverages are particularly well known and these are usually a dry mix of a soluble coffee powder and a soluble beverage creamer. Products of this type are known which contain pockets of gas which upon dissolution of the powder produce a foam so that on the addition of water or milk (which will usually be hot), a whitened coffee beverage is produced having foam on the surface which resembles, to some extent at least, traditional Italian cappuccino. Examples of gassed soluble beverage creamers are described in EP-A-0 154 192, EP-A-0 450 310 and EP-A-0 885 566. Soluble beverage creamers which contain chemical foaming agents are also known. The formation of a foam is dependent on the powder containing an ingredient, generally a protein such as casein, which is capable of stabilizing the foam.
In many fields, the presence of gas-generating chemicals is undesirable, for example because of their effect on flavor, or they may even be prohibited. There is a need to provide water soluble or water dispersible carbohydrate based powders and tablets with improved reconstitution properties in water without the need to use such chemical dissolution aids.